Mechanism for feeding steel disks or the like



March 22, 1960 R. TONELLl EI'AL 2,929,532

MECHANISM FOR FEEDING STEEL DISKS OR THE LIKE Filed Oct. 3, 1955 6 Sheets-Sheet l N VEN TQRS E0 er aneilz Ric 0 clziaru iti'rzi March 1960 R. TONELLI ETAL 2,929,532

MECHANISM FOR FEEDING STEEL DISKS OR THE LIKE Filed Oct. $1955 6 Sheets-Sheet 2 Fff March 22, 1960 R. TONELL! ETAL 2,929,532

MECHANISM FOR FEEDING STEEL DISKS OR THE LIKE Filed 001:. 3, 1955 6 Sheets-Sheet 5 Fig? 4 INVENTORS Eqger T flellz' March 22, 1960 R. TONELLI ETAL 2,929,532

MECHANISM FOR FEEDING STEEL DISKS OR THE LIKE Filed Oct. 3. 1955 6 Sheets-Sheet 4 March 22, 1960 R. TONELLI EIAL 2,929,532

MECHANISM FOR FEEDING swam. msxs OR THE LIKE Filed Oct. s, 1955 s Sheets-Sheet s Cenlering Pins firakes Heading Plunye NVENTQRS leoqcr anellr- March 22, 1960 R. TONELLI ETAL 2,929,532

MECHANISM FOR FEEDING swam. DIsKs OR THE LIKE 6 Sheets-Sheet 5 Filed Oct. 5, 1955 191 line MECHANISM FOR FEEDKNG STEEL DISKS OR THE LIKE Roger Tonelli and Riego Chiaruttini, Chicago, 111., as-

signors to Radio Steel 8; Mfg. (30., Chicago, 331., a corporation of Illinois Application Gctoher 3, 1955, Serial No. 537,959

6 Claims. (Cl. 22111) This invention relates to a new and improved feed mechanism for use in cooperation with a conveyor to feed steel disks or the like to the conveyor.

One principal object of the present invention is to provide a new and improved feed mechanism adapted to transfer steel disks or the like from stacks held in a magazine to a conveyor or some other receiving device.

A further object is to provide a new and improved feed mechanism of the foregoing character which is particularly well adapted for use in feeding wheel disks to a machine for welding pairs of the disks together face to face to form wheels for coaster wagons or the like.

it is another object to provide a new and improved feed mechanism of the foregoing character which is entirely automatic in operation and requires no attention from the operator except for occasional filling of the magazine with stacks of disks.

A further object is to provide a new and improved feed mechanism in which the steel disks are removed one by one from the magazine by magnetic devices, are carried to the conveyor, and then are discharged onto the conveyor by mechanical elements which push the disks ed the magnetic devices.

It is another object to provide a new and improved feed mechanism in which the stack of disks at the feed position is automatically raised in the magazine to maintain the top of the stack at a substantially constant level, and in which the magazine is automatically indexed, responsive to the depletion of the stack, to bring a fresh stack of disks into the feed position.

A further object is to provide a new and improved feed mechanism of the foregoing character which is etfective in operation yet is reasonably simple in construction and low in cost.

Further objects and advantages of the invention will appear from the following description, taken with the,

accompanying drawings, in which:

Figure 1 is a plan view of a wheel welding machine equipped with a pair of feed mechanisms constituting illustrative embodiments of the invention;

Fig. 2 is a side elevational view of the wheel welding machine;

Fig. 3 is an elevational sectional view of one of the feed mechanisms, the view being taken generally along a line 3-3 of Fig. 1;

Fig. 4 is a fragmentary vertical sectional view, taken generally along a line 44 in Fig. 3, to show various details of a mechanism for indexing the magazine of the feed mechanism;

Fig. 5 is a horizontal sectional view, taken generally along a line 5-5 in Fig. 4;

Fig. 6 is a fragmentary vertical sectional view, taken generally along a line 6-6 in Fig. 3, to show various details of a mechanism for raising the stacks of disks in the magazine to maintain the tops of the stacks at a substantially constant level;

Fig. 7 is a fragmentary horizontal sectional view, taken generally along a line 77 in Fig. 3;

Fig. 8 is an elevational view of a wheel adapted to be assembled and welded by the machine of Fig. 1 and embodying two of the disks adapted to be fed by the feed mechanism;

Fig. 9 is a sectional view of the wheel, taken generally along a line 99 in Fig. 8;

Fig. 10 is a diagrammatic representation of the electrical and air-actuating system of the feed mechanism; and

Fig. 11 is an electrical diagram which supplements Fig. 10.

If the drawings are considered in greater detail, it will be seen that Figs. 1 and 2 illustrate a machine 20 adapted to assemble and weld wheels 22 of the type shown in Figs. 8 and 9. It will be understood, of course, that the assembly machine 20 might be arranged to assemble various other components. For the purpose of illustration, however, it will be noted that the wheel 22 comprises a pair of identical disks 24 which are welded together back to back. As illustrated, each of the disks 24 has a concavo-convex central portion 26 together with an outwardly turned marginal flange 28. Between the central portion 26 and the flange 28, each disk has an annular convolution 30. In the wheel 22, the convolutions 39 of the two disks 24 abut against each other and are secured together by a plurality of spot welds 32.

The central portion 26 of each disk has an axial aperture 34 adapted to receive a wheel shaft. It will be seen that the flanges 28 define a peripheral groove or channel 36 adapted to receive and retain a tire. Thus the wheel 22 may be employed in coaster wagons or other wheeled devices.

To assemble and weld the wheels 22, the machine 29 is provided with a conveyor 38 adapted to receive the disks 24 in their assembled relation. The conveyor 38 carries the assembled disks 24 to a spot welding unit 46 which forms the spot welds 32.

In this instance, the conveyor 38 takes the form of a rotatable, horizontally disposed table adapted to be indexed or rotated intermittently by a power-operated indexing unit 42 of any suitable construction. To receive and locate the disks 24, the table 38 is fitted with vertical pins 44. The illustrated spot welder 40 is capable of welding two wheels at once. Accordingly, the pins 44 are mounted in pairs on blocks 46 which also support sets of lower welding electrodes 48. In the illustrated arrangement, four of the welding electrodes 48 are distributed around each pin 44. Corresponding upper welding electrodes 50 are provided on the spot welder 49.

When the assembled disks are indexed to the spot welder 46, the upper welding electrodes 50 are moved downwardly so that the assembled disks will be clamped together between the upper and lower electrodes 54} and 48. Welding current is then passed through the disks between the electrodes to complete the spot welds 32. The completed wheels 22 may be subsequently removed from the conveyor 38 by any suitable discharge mechanisrn.

The disks 24 are loaded onto the conveyor 38 by a pair of feed mechanisms 52 and 54 which are identical except that the mechanism 52 is adapted to feed the disks to the conveyor with the annular convolutions 39 projecting upwardly, while the mechanism 54 feeds the disks with the annular convolutions 30 directed down wardly. In this way, the disks 24 are assembled with the convolutions 30 in engaged relation. In view of the substantial identity of the mechanisms 52 and 54, it will be sufiicient, for the most part, to describe the mechanism 52. It will be seen that the feed mechanisms 52 and 54 are spaced along the periphery of the conveyor 38 and are adapted to deposit the disks successively, one upon another.

.aeaassa V r controlled thereby. For each reciprocation, one ofthe pickup devices 62 is movedjtoward and away from the top of each stack of disks 24 at the feeding position in the magazine 53. The pickup device 62 is effective to take the topmost disk 2- off the stack.. When the head 56 is subsequently indexed, the disk is carried into alignment with one of the pins'44 on the conveyor 38.

56 might also be varied in construction but'is illustrated a as a rotatable head having pick-up devices 62 arranged to take the topmost disks 240E the-stacks. It will be seen that the pick-up devices 62 are arranged in two diametri cally opposite pairs on the transferhead 56. Thus; the topmost disks are removed from two of the pockets 69 simultaneously and are carried to the conveyor- '38. Then, the disks are discharged onto the pairs of pins 44 carried by the blocks 46. When the stacks of disks at the feed position. are depleted, the magazine 58 is automatically indexedto bring fresh stacksintoposition. From time to time, the operator may replenish the deplated stacks so' that'the operation of the machine may continue without interruption.

As to the detailed arrangement of the transfer head for vertical reciprocation and rotation about a vertical axis. in this instance, the head 56 is. carried by a hollow rotatable verticalshaft 64 supported by upper and lower bearings 66 and 6%. A gear 70 is mounted on the shaft 64 and is arranged to mesh with a. larger gear 72 carried by the conveyor turntable 38 Thus, the head 56 is positively driven by the conveyor 38 and is indexed bythe mechanism .2 Whenever the conveyor is indexed. The ratio oflthe gea.'s 7i) and 7.2 is such as to rotate the transfer head 56 through one-half revolution when the conveyor turntable 33 is indexed through. the angular interval between the blocks 46.

To provide for vertical reciprocation of the head 56,

' the rotatable shaft 64 is connected to the head by means of a pair of telescopically engaged tubular elements 74 and 76 mounted rigidly on the shaft and the head, re-

. spectively. The elements 74 and 76 may be non-circular,

as shown, or may be keyed or splined together to permit relative vertical movement between the elements while preventing relative rotation. Asillustrated the elements 74 and'76 are substantially square in cross section 'Various means might be provided to effect vertical reciprocation of the transfer. head 56. In the illustrated construction, such reciprocation is brought about by a double acting air cylinder 80 or some other type of linear fluid motor. Disposed withinthe cylinder 80 is a piston 82 having a piston rod 84 connected to .a hollow vertical shaft 86 by means of a fitting 88. It will be seen that the fitting i8 is received as a plug in the lower end of the hollow shaft 86. A threaded lower end portion 90 'of'th'e fitting 88 is screwed into the upper end of the Toprevent rotation of the hollow shaft 7 .86 and the piston 82,; a laterallyextending guide pin piston "rod 84.

"the head and the shaft while preventing relative vertical movement. In this instance, the hollow shaft 86 is. employed to carry air to the head 56. Thus, an air supply hose98 is mounted in an inlet port 109 formed On the next downward movement of the head 56, the disk is discharged on to' the. underlying pin 44.

The pickup devices 62 might "be arranged in various ways so as tobe'capable of takingthe.topm stfdisks ofi the stacks in the magazine pockets 6%). However, in the illustrated construction, each of thepickup devices 62 is provided with a permanent magnet 1G4 to pickup the disks. It will be seen that the illustrated magnet 104 is in the form of a short ring equipped with inner and outer pole pieces 166 and 108 of annular form. The

a pole pieces 166 and 108 have radial flanges 110 and 112 '56, it will be seen from Fig. 3 that thehead is mounted which are bolted together 7 with the; ring-shaped; magnet 194 clamped therebetween. Bolts ll i are employed to. secure the pickup devices 62 to the head 56. The actual poles of the magnet are formed' by hollow cylindri cal portions 116 and 118 of the pole pieces 1&6 and 108. It will besseen that the poles 116 and 118 extend downwardly from the flanges 118 and 112. The pole 116 is disposed within, the pole 113 in 'spaced concentric relation; thereto. In this: instance, the inner pole 116 is made slightly longer than the outer pole 118'to conform to the'shape of the disk 24.. It will. beunderstood that this relation isfrevers'ed'in the feeder 54,inasmuch as the position or the disks 24 isreversed.

The effective strength, of. the magnet 164 is regulated by means of a spacer 12%? in the form'of a nonmagnetic in the fitting 88 and communicating with theinterior of the hollow shaft 86. A rotatable air distributing head 7 102 is mounted on the upper end of the hollow shaft I By means'of a solenoid operated 4-way control valve 193, the'air cylinder 89 is energized so as to reciprocate the head 56. downwardly and then upwardly during the dwellperiodof the conveyor turntable 38. The valve llifii is connected electrically to the indexer42. and is feeder 54- inasmuch as the .that the spacing ring 120 has an endsurface 122 which is conformed'to the shape, of the. disk 24. The. shape. and length of the spacer 120 will be different on the disks handled by the feeder 54 are inverted. I The ejection of the disks 24 from the feeders 62 might be accomplishedin various ways but in this instance is efiected by means of a pusherior plunger124 which is provided on eachrpffthe feeders 62. It will be seen that the plunger 124 isrecipr'ocable vertically in aibearing 126 carried by the pickup device" and is arranged to extend downwardly within the inner pole'116. The pusher 124 might be, actuatedin various ways, but in this case it is operated bya linear fluidnibtor intheform of a double acting air cylinder I28. A piston 13ers disposed in the cylinder 128 and is connected directly to the upper end of the pusher 124. 5

Each of the air cylinders 128'is adapted to be energized by means of a 4-way control valve 132 which receives air from the distributor headrlin through a. lengthrof hose or tubing 13 4 The valve 132 is'operable tosupply air. pressure alternately to the upper and lower ends of the cylinder through hoses or tubes 136and 13-8;

Each of the'illustrated control valves 3.32is operated by a shaft or rod 149 which is rec'iprocable vertically in the head'54. When the shaft 14% is in itslowermost position air is supplied to the lower end of the-air cylinder 123 so as to raise the plunger 12 4. Molvem'ent of the shaft 140 to its uppermost position. shifts the supply of air to the upper end of the cylinde r 128, with the result that the plunger 1241s moved downwardly so as to push the disk off the magnet 104. In theillustrated arrangement, such vertical rnovernent of the shaft 344? is eifectedin response to vertical reciprocation of fthe transfer head 56. The movement of the shaft 140 is brought about by means of a stationary cam 142 which is engagcable with a roller 144 carried by the lower end of the shaft 149. The cam 142 has upper and lower flanges 146 and 148 adapted to move the shaft 140 downwardly and upwardly.

The cam 142 is disposed locally along the path of the transfer head 56 so as to actuate only the control valve 132 corresponding to the pickup devices 62 at the delivery position over the conveyor 38. It will be recalled that the pickup devices are arranged in pairs and that the devices of each pair act simultaneously. Thus, each of the control valves 132 may be employed to actuate both of the pickup devices of each pair.

When the transfer head 56 moves downwardly, the roller 144 engages the lower flange 148 of the cam 142. Accordingly, the shaft 140 is moved upwardly so as to shift the valve 132 into a position in which air will be directed to the upper end of the air cylinder 128. The plunger 124 of each pickup device 62 at the delivery position will then be pushed downwardly against the disk 24, with the result that the disk will be pushed oi? the magnet 104 on to the conveyor 38.

To center the disks 24 on the pickup devices 62 and to insure delivery of the disks onto the conveyor pins 44, each of the pickup devices is provided with a centering pin 154 which projects downwardly from the ejecting flange 124 and is slidably received in an axial bore I156 formed therein. A spring 158 is disposed in the bore 156 to bias the pin 154 downwardly. The downward movement of the pin 154 is limited by an enlarged head 1643 which is formed on the upper end of the pin and is engageable with the upper end of an apertured plug 162 mounted in the lower end of the bore 155. it will be seen that the pin 154 projects downwardly through the plug 162 and is adapted to be inserted through the axial apertures 34 formed in the steel disks 24.

Thus, the retractable pin 154 enters the aperture 34 in the topmost disk 24 of the stack in the magazine pocket 60 when the disk is picked up by the pickup device 62. Accordingly, the disk is centered relative to the pickup device. When the pickup device is indexed into its delivery position over the conveyor 33, the transfer head 54 moves downwardly to deposit the disk over the underlying conveyor pin 44. The lower end of the centering pin 154 engages the upper end of the conveyor pin 44 so that the disk 24 will be guided downwardly on to the conveyor pin 44. During the remaining downward movement of the transfer head 56, the centering pin 154 is pushed upwardly against the yieldable biasing action of the spring 158.

The detailed arrangement of the magazine 58 may be varied, but in the illustrated construction, each of the magazine pockets 60 is generally cylindrical in form and is provided with an outwardly facing vertical slot tea to provide for easy insertion of the disks 24 into the pockets. A ledge 166 is provided at the bottom of each pocket to support the stack of disks 24. Provision is made for raising the two stacks of disks 24 at the feed position so that the top of each stack will be maintained at a substantially constant level. For this purpose, the feed mechanism 52 is provided with a pair of elevating devices 168 which are substantially identical. Each of the devices 168 comprises an elevating plunger 17% adapted to engage the bottom of the corresponding stack of disks 24. It will be seen from Fig. 3 that the plunger 170 is actuated by a double acting air cylinder 172 but it will be understood that various other means might be employed for this purpose. The cylinder 172 contains a piston 174 which is connected to the plunger 170 by means of an elongated piston rod 176. To guide the plunger 170 for vertical movement, a pair of slides 178 are mounted on the plunger and are arranged to slide along vertical guides 18%.

During normal operation of the feed mechanism, air

is supplied to the lower end of the double acting cylinders 172 by control means that will be described in greater detail subsequently herein. The compressed air biases the plunger 174 upwardly with the result that the plunger tends to raise the stack. The raising movement is controlled by means or" a brake 182 (Fig. 6) which acts upon both of the elevating devices 168. While various brake arrangements might be employed, it will be seen that the illustrated brake comprises a pair of shoes 184 and 185 adapted to engage the piston rods 176 and thereby restrain upward movement of the plungers 179. A double acting air cylinder 138 is employed to actuate the shoes 184 and 186. It will be seen from Fig. 6 that the shoe 184 is integral with the air cylinder 188 While the shoe 186 is connected to a piston 190 sliclably mounted in the cylinder.

The brake 182 is arranged to be released in response to downward movement of the transfer head 56. The release of the brake 182 permits the elevating plungers 79 to raise the stacks until the topmost disks engage the pickup devices 62. The brake 182 is arranged to be engaged when the transfer head 56 moves upwardly. in this way further upward movement of the stacks is prevented.

Various brake control arrangements might be employed, but it will be seen from Fig. 10 that each of the illustrated brake cylinders 188 is controled by means of a 4-way valve 192 operable by means or" a pair of solenoids or coils 194 and 1%. The brake 182 is engaged by energizing the coil 194 and is released by energizing the coil 196. The arrangement is such that the coil 196 is energized as the transfer head 56 approaches its lowermost position, while the coil 194 is energized in response to upward movement of the transfer head 56. This is brought about by a single pole double throw limit switch 1% operable by the transfer head 56.

The magazine 53 is arranged to be indexed in response to depletion of the stacks of disks 24 in the pockets 6% at the feed position. Actually, the magazines 5% of the two feed mechanisms 52 and 54 are indexed simultaneously. Various arrangements might be provided for indexing the magazine 58. However, in this instance, the magazine is mounted for rotation on a vertical shaft 2% carried by upper and lower bearings 2%2 and 2&4. It will be seen from Fig. 4 that a rotary air motor 206 is provided to rotate the magazine 58. A pinion 208 is provided on the air motor and is arranged to mesh with a gear 210 mounted on the lower end of the magazine shaft 2%. The motor 2% is arranged to be energized in response to upward movement of the elevating plungers 17% in a manner to be described in detail below.

After the magazine 53 has been indexed by the motor 236, the magazine is locked in its indexed position by means of a tapered locking or locating pin 212 (Fig. 3) adapted to be received in any one of a series of tapered recesses 214 formed on the underside of the magazine 58. In this instance, three such recesses 214 are provided. The pin 2-12 is slidable vertically in a cylindrical guide 216 and is operable by means of a double acting air cylinder 213. A li ht spring 223 biases the pin 212 upwardly to lock the magazine 58 during intervals when the feed mechanism is shut down.

In this instance, the operation of the indexing motor 2% is controlled in response to movement of the locking pin 212. Thus, a valve operating pin 222 projects into the guide 226 behind the locking pin 212. When the locking pin 212 is withdrawn downwardly, it cams the pin 222 out of the guide 226 and thereby operates a valve 224 which energizes the air motor 2436. When the locking pin 23.2 is moved upwardly by the air cylinder 218, the pin 222 is released and the air motor 2th: is thereby de-energized.

Provision is made for stopping the magazine 58 in its indexed position. For this purpose, the magazine 58 is provided with a plurality of stop fingers 226 which are slidable radially in guideways 228 formedjn thebody of. the gear 219 at the lower end of the magazine shaft 2%. A movable stop member 234 is disposed in the path 'ofthe stop fingers 226. From. Figs. 4 and 5, it will'be 'seen that the stop member 235) is slidable in a stationary the' air cylinder 218 for the locking pin 212. The two air cylinders218 and 234 are adapted to be energized in common by a 4-way valve 236. It will be seen that the arrangement issuch that the locking pin 212 and the stop member 2359 are advanced and retracted simultane ously. Atthe endot the indexing movement of the magazine 58, the locking pin 212 and the stop member 23 are advanced, in a manner to be described below. Asa result, the stop member 236 pushes the stop finger 226 inwardly to its retracted position shown in dotted lines in Fig. 5.. For this purpose the stop memberZZaQ is formed with a shoulder 23% engageable with the outer end of the sto fin er 226. A s iin ressed detent ball l V a g Zli)'frictionallyretains each of the fingers 226 in either its retracted or its extended position. V

In its advanced position, the stop member 236 still interlocks with the finger 226 so that further rotation of the magazine 58 is prevented. i-iowever, thestop member 23!) is retracted, along with the locking pin 212, at the beginning of the next indexing cycle. In this way,

7 the stop member 230 is disengaged from the stop finger 226. During the indexing rotation of the magazine 58,

. the stop fingers 225 are extended by means of a stationary eccentric cam in the form of a roller 242.

in this way, 'eachof the fingers 226 is extended in turn for ngagement with the retracted stop member 230.

It, will be of interest to note that the feed mechanism 52 is mounted on a frame 244 which 'is supported by means of one or more levelling screws 246. Thus, the level of the feed mechanism 52 may be adiusted for proper cooperation with the conveyor 38. An adjustable ends of: the air cylinders 172. It will be seen from Fig.

10 that the elevating air cylinders 172 of each feed mechanism are controlled by a 4-way valve 252 operable by solenoids or coils 254 and 256 which maybe energized to move'the plungers 179 up and down respectively. As each stack, of discs 24' is. depleted, the corresponding plunger 179 approaches its upper limit of travel. Before i the stack is fully depleted, each of the plungers'170.

closes a limit switch 158, four such switches being provided and being connected inparallel between a power linewire 260 and a lead 262. Alternating current power is supplied to the feed mechanisms 52'and'54 for con trol purposes by theline wire 260 and a companion line wire 264. Closure'of any one of the limit switches 25S energizes a transformer 266 through a circuit that may be traced through the limit switch 253, a lead 262, the primary of the transformer 266, a lead 268, and normally closed contacts 27911 of a time delay relay 27%. The secondary of the transformer 266 energizes the down coils 256 of the elevator control valve 252 through a circuit that may be traced along a lead 272, normally'closed contacts 274d of a relay 274, and a lead 276. In this way, the valve 252 is shifted so as to direct air. to the upper 176 downwardly. 7

To release the brakes 182, the limit switches 258. are also arranged to energize a relay 278 through a circuit that may be traced between the line wires 260 and 264 through any one of the limit switches, 258, the lead 262, the relay 27S, and the normally closed contacts 270a of the time delay relay 270. Energization offthe relayf278 ends of the air cylinders 172 and therebybias plungers closes a circuit to the disengaging coils 1960f the brake.

control relay 192 through acircuit that includesa secondary winding sea of a transformer 282. The circuit may be traced from the secondary winding 280 to the coils 196 through a lead 28 branch leads 286 and 288, normally open contacts 278c and 278s of the relay 278, and

branch leads 2% and 292.

Energization of the relay. 278. also renders the limit switches 198. inettective to control the brakevalves 19,2.

. ZSfi'through a lead 294, the normally closed contacts 273d, and the lead 284.

Energization of the relay 278 closes a holding circuit for the relay and the transformer-266; This holding cir: cult bypasses the limit switches 258 andmay be traced from the line wire 269 to the linej'wire 264 through a lead 296, normally open contacts278a of the relay278, the relay 278, a lead 298, andthe normally closed contactsf27lla of the time delay relay 270. It will be seen that the holding contacts 278a are connected between the lead 262 and the line'vrire 26flfso7as to bypass the limit switches 2153. a

When the relay 278 is energized, the welding machine 28 and the conveyor 38 are disabled by-the opening of normally closed contacts 27812. Leads 300 and 302 are connected to the contacts 27% and'are adapted to extend to the indexing mechanism 42 of the conveyor 38 to disable the conveyor and thereby arrest movement of the conveyor and the transfer head 56 until the indexing of the magazine 58 has been completed. With the compressed air supplied to the upper ends of the elevating cylinders 172 and with the brakes 182 released, the plungers 1.70 are moved downwardlyuntil they close the limit switches 364, all four of which are connected in series. When. all of the plungers 170 have "been fully lowered and all of the limit switchesSM have been closed,

a circuit is' completed that will be'elfective to. initiate indexing movement of the magazine 58. Initially, a relay 3% is energized through a circuit that'maybe traced from the line wire ass to the line wire 264 through the limit switchesfifi l, the relay 306, a lead 368, normally closed contacts 27% of the relay 274', a lead 310, a pair of series connected normally closed limit switches 312,

a lead 314, the leadfZS, and the normally closed con-' tacts 27am Energization of the relay 306 is eflfective to, retract the locking pin 212 and the stop member 23d. The control valve 236 for the pin 212 and the'membcr 23% has advancing and retracting controlv coils314 and 316. An energizing circuit may be traced from the transformed secondary 280 to the retracting windings 316 through a lead 318, normally open contacts 3062 of the relay 3G6, and a lead 320. Q. 7

Operation of the relay 306 is elfective to operate the relay 274. An energizing circuit'for the relay may be traced between the line wires 260 and 264 through the limite -s itches 334, a lead 322, normally open contacts,

396a of the relay 396, a lead 324, the relay 274, a'lea d 326, the lead 268, and the normally cldsed'contaets'270a,

336 is maintained by normally open contacts 306cwhich are connected in parallel with the contacts glfllp Uperation of the relay 274 closes a holding circuit that -may be traced between the line wires 260 and 264 through a lead 328, normally open contacts 274a on the relay 274, a lead 330, the relay 274, the lead 268, and the normally closed contacts 270a. 7

It will be recalled that the retraction of the locking pin 212 actuates the valve 224 and thereby energizes the indexing motor 206. Accordingly, indexing rotation of the magazine 58 commences. The limit switches 312 remain closed until the indexing movement is nearly completed whereupon cams 332 on the magazines 58 open the limit switches 3-12 momentarily. This de-energizes the relay 306 but not the relay 274. Energization of the relay 274 is maintained by the holding contacts 274a. The

de-energization of the relay 306 is effective to cause advancing movement of the locking pin 212 and the stop member 230. This is brought about by energization of the advancing coils 314 on the control valves 236. An energizing circuit may be traced between the transformer secondary winding 280and the advancing coils 314 along the lead 318, normally closed contacts 306b of the relay 306, a lead 334, normally open contacts 274a of the relay 274, and a lead 336. It will be recognized that this circuit is completed only when the relay 274 is energized with the relay 306 de-energized. This is the condition that exists upon the opening of the limit switches 312.

As already explained, the advancing movement of the locking pin 212 releases the motor control valve 224 and thereby de-energizes the indexing motor 206. The stop member 230 arrests the rotation of the magazine 58 and prevents the magazine from travelling beyond its indexed position.

The de-energization of the relay 306 results in energization of the time-delay relay 270, which in turn causes de-energization of all the other relays and also de-energization of its own operation. In other words, the timedelay relay 270 serves as a cancelling device to restore the relay system to its normal condition. An energizing circuit for the time-delay relay 270 may be traced between the line wires 260 and 264 through the lead 296, the relay 270, a lead 338, normally open contacts 274a of the relay 274, normally closed contacts 306d of the relay 306, the lead 310, the limit switches 312, the lead 314, the lead 268, and the normally closed contacts 270a. Thus, the time-delay relay 270 can be energized only when the relay 274 is energized while the relay 306 is de-energized. Moreover, the limit switches 312 must be closed. In arriving at its indexed position, each of the magazines 58 overruns the corresponding limit switches 312 with the result that it resumes its normally closed position. When both of the limit switches are closed, the time-delay relay 270 is energized. Closure of the limit switches 312 does not re-energize the relay 306 because the energizing circuit is broken by the contacts 274b.

The relay 270 is of any conventional or suitable type which provides a time delay between energization and opening of the contacts 270a. A'time delay of one second or less is adequate to permit seating of the locking pin 212." When the contacts 270a "open, all of the energized relays are de-energized. More specifically, the relays 274 and 278 are de-energized since their energizing circuits include the contacts 270a. Moreover, the relay 270 cancels its own operation since its own energizing circuit includes the contacts 270a. With all of the relays de-energized, normal operation of the conveyor 38 and the feed mechanisms 52 and 54 is resumed. Such resumption of normal operation is brought about by closure of the normally closed contacts 278b.

it will be recalled that the de-energization of the relay 306 shifts the elevator control valves 252 to their raising positions. Since the brakes 182 are released at this time, the plungers 170 immediately start to rise toward the bottoms of the stacks of disks 24 in the magazine 58. As soon as the contacts 278a open, the relay 278 is de-energized. Accordingly, the limit switches 198 are reacti- -vated, with the result that the brakes 182 are engaged until the transfer head 56 again moves downwardly.

While the operation of the feed mechanisms 52 and 54 has already been described fully, it may be helpful to offer a brief summary. During normal operation of the welding machine 20, the conveyor turntable 38 rotates intermittently to bring successive sets of assembled disks to the spot Welder 40, which is capable of welding two pairs of disks simultaneously. The gears 70 and 72 on the transfer head 56 and the table 38 are effective to rotate the transfer head 56 through one-half revolution for each interval of advancing movement of the table. Thus, the pairs of pick-up devices 62 are positioned alternately over the magazine pockets 60 and the conveyor table 38.

During the dwell periods of the conveyor 38, the air cylinder is energized so as to move the transfer head 56 downwardly. Two of the pick-up devices 62 engage the topmost disks in the magazine pockets 60. The disks are attracted to the permanent magnets 104 so that the disls will be picked up when the transfer head 56 again moves upwardly.

The downward movement of the transfer head 56 is efiective to release the brake 182, with the result that the air cylinders 172 push the elevating plunger 70 upwardly to raise the stacks of disks against the pickup devices 62. As soon as the transfer head 56 moves upwardly, the brake 182 is again engaged to prevent further upward movement of the stacks.

The transfer head 56 is returned upwardly by the air cylinder 80. During the next indexing movement of the conveyor 38, the transfer head 56 is rotated to bring the newly taken disks over the conveyor. When the transfer head 56 again moves downwardly, the roller 144 strikes the lower flange 148 on the cam 142. Accordingly, the shaft is moved upwardly so as to operate the valve 132 in such a manner as to supply air to the upper end of the air cylinder 128. This moves the ejecting plunger 124 downwardly so as to push each of the disks off the corresponding magnet 104. The yieldable guide pin 154 engages the upright pin 44 on the conveyor so as to guide the disk downwardly.

When the transfer head 56 is moved upwardly, the roller 144 strikes the upper flange 148 so as to reverse the valve 132 and move the plunger 124 upwardly. This goriiditions the pick-up device 62 for reception of another As the stacks are depleted, the elevating plunger-s move upwardly. At a predetermined point, the plunger closes the corresponding limit switch 258 and initiates indexing movement of the magazines 58. The control system is efiective to retract the looking pin 212 and the stop member 230 of each magazine 58. The retraction of the locking pin 212 operates the valve 224 and thereby energizes the air motor 206, which is effective to rotate the magazine 58. The rotation of the magazine 58 is arrested when one of the fingers 226 engages the stop member 230. Just before the magazine 58 comes-to rest, it passes over the corresponding limit switch 312, with the result that the locking pin 212 and the stop member 230 are advanced. In this way, the magazine 58- is accurately positioned. The advancing movement of the locking pin 212 de-energizes the indexing'motor 206. Normal operation of the machine is then resumed.

It will be recognized that the feed mechanisms are e'n'ective in operation yet are reasonably simple and low in cost. require no attention except for occasional re-filling of the magazine pockets by the operator.

Various modifications, alternative constructions, and equivalents may be employed without departing from the true'spirit and scope of the invention as exemplified in the foregoing description and defined in the following claims.

The mechanisms are virtually automatic and responsiveto disengaging movement of said plunger for f l mined position.

I I1 We claim:

1.'I n'a mechanism' for 'feedirig steel disks or the like 7 with c'entralapertu'res thereinfroin a stack'ithereofpthe "combination comprising a rotary transfer head having a pickup" device thereon, means mountingflsaidhead for *rot'ation about an aXes parallelto said stack, means for rotatablyindering said head to bring said" pickilpfdevice fto alig nrn'ent withthe stack, means mounting said head f for'reciprocation along its axis toward andaway-fror'n 'the stack, means for r'eciprocating said headw'ith said pickup device aligned with the stack, said pickup device 7 'having a ring-shaped magnet for picking up'the top disk ,in the stack, an annular spacerelement forengaging the disk"and spacing the same awayyfrom said magnetjto "adjust the eflective strength thereof, anaxialguidef pin for entering the aperture in the disk,a 'hollovsf'plunger the apertures in thedisks of the stack. c'hanism for feeding V disks or the like, the combination comprisinga magazine ha'vingia' pocket for holding {a stack of the disks, a pickup head inovable toward and away from the top of the stack for removing the top disk in the stack, 'a movable pusher "engageable with the bottom of the stack,[an' air cylinder for biasing said pusher upwardly to raise the stack against said'pickup head with said head moved toward the stack, a'b'r'ake for preventing upward movement of said pusher, first control means forreleasing said brake in' responsefto substantially full movement of said pickup head toward. a the top of the stack, said first control means being efiem ,tive to set said brake in response to initial movement of said pickup ahead in the opposite direction, and second icontrol means operative in response to depletion of the .stackto actuate said air cylinder'in a direction to lower 'said movable pusher.

3. In a mechanism for feeding disks or the likefthe combination comprising a rotatable magazine having a plurality of pockets tohold stacks of the disks-for indexing;movement,into a feed position, a motor for rotatably indexinglsaid magazine, a movablelocking plunger en- 'gageable with, said magazine for locating said magazine in its indexed position, said magazine having locking elements thereon for engagementby said'plunger, means responsive to depietion'of the stack at said feed'position for disengaging said plunger from .said magazine-means energizing said'motor, a'plurality of radially slidable'stop fingers mounted on said magazine, a movable stop me'rm ber disposed at a predetermined position inthe paths'of said stop members for stoppingsaid magazine in its-indeXed positions, means for de e'nergizing said motor with said magazine in its indexed positions, m'eans,for advancing said locking plunger into engagement ithsaidfmagazine, means for advancing said stop member and -thereby effecting radially inwardrnovement of said'fstbp'finger at said predetermined position, means for retracting said stop member to 'clear'said stop finger, and afcamffor extending said fingers as-thg'z'y approach 's'aid prede'ter- 4. in a mechanism for feeding disks'or; the like, the

c ornbination' comprising a rotatablernagazine having a plurality of pockets to hold stacks of the disksfor, indexing movement into a feed position, a motor for rotatably indexing said magazine, means responsive to depletion v of the stack at said feed position for energizing said 7 v 'motor, a plurality of radially movable stop fingers assess:

12 untedfon aidiniaga'zide, a movablestoprhember disdi at a}predetermined* pos'ition "in the 1 paths of" said stop rn e'nilj 'ers forffstopping a said "magazine in its indexed posiaoasimsns-rsr de energizing saidfniotor afterpre- 5 determined indexing movement of said magaZinefmeanS iorfadvancing "saidf stop member and thereby effecting j radially awarsmbvememor saidstop' finger at said predetermined position, means for retracting said stop memlb ercto,cleansiaidstop fingerfaiida cam for extending i said f ngers "as they approach said predetermined position. Sjina mechanism for feeding steelfdisks or thelike, tliefoomhifiation {:ompri'si'rigja rotatable magazine havinga plurality lofangularlyspaced vertical pockets for "holdingi s'tacks of the disks 'for indexing movement into 15 Ta ree position, p'oweri means for indexing: said magazine, ra ro't'atable,transfer head having a pickup device :thereonforf rr'ying the'disks 'frordthe feed polsitionto w ans for reciprocating said-pickupay' from the top offthe'stack, means Q on 'fsaid 'picknp ider/ree for taking tthe ftoprnostf disk ofit T the stack, a 'reciprocable lifting 'rneinb'er for raising the j'stack atthef f ed pos tion; anair, cylinder for biasing i'saidflifting'mmb fup w'ardly to raisethe-stack, a brake forf preventing lifting *mbvement'br saidlifting' member, 25 "first eontrol fnie'ansi responsive 1 to: siib'stantially full down- Wardmovemeht of said pickupfievice forreleasing said fbrake to provide forupwardmovement f the stack by said air cylinder 'agai'nstfthe pickup'device; said first control means; being operative to "s'ets'aid brake in response ond'control"means 'resp'o'nsiveto "depletion of thestack for actuating said air cylinderin a dir'ection'to lower said liftingim'e'mb'er, "and third"'controlmeans responsive to substantially full lowering movement ofsaidliftingme'mher for actuating said powerfm'eans' and thereby indexing said magazine to'bring' a"freshstacki'rlto the feed position. I u r v 7 u "'6. 'In'a"mech'anism"1for feedingdisks' or the like, the comlji'nation comprising a rotatable magazine having a plurality, .of pfoeketsj'to hold stacks of'the disks for indexin movement as 'afifeed' position; a rotary-motor for" rotatably'" indexing "said: magazine, ajmovable' locksing member ngage'abie'wi lrsaid; 'rn'agazine for locating lisaidiriag'azmein' itsindexedposition, said magazine having. locking stamens Ith'ereon fforengajgem'ent by, said tmember, 'iibwe mean forinpving' said'loeking'mernber toward and mayhem said magazine, first control means reap-basins to'depletiofiof"the' stackat said fe'ed position ,for'".ac'ti1ating' saidpov'ver means in a direction to disengagesaid nie'r nher frorn' said magazine, s'ec'ond contr Y-nreans responsive to disengaging movement of said V niem'oer forenergizing"said":inotor,' and third control ,"meansrespons ve to prede'trrnin'ed indexing" the V :of said magazine for actuating said power means in an ,opposite direction to advance said member against's'aid lmaga z'ine;saidisecond control means 'tirereupon 1 being effective to stop 's aid' m'o'tor.

file of thisfpatent to'initialflupward'movement offs'aid pickup device, sec- 

